Coordinate Adjective Clauses

Two or more coordinate clauses may be joined to make one compound clause.

1. The polar bear, which lives in the Arctic regions and whose physical constitution is wonderfully adapted to that frigid climate, sometimes reaches temperate latitudes.

2. The polar bear sometimes reaches temperate latitudes when the floes break up and when the ice drifts southward.

In the first example, the italicized words form a compound adjective clause, modifying the noun bear. It consists of two coordinate adjective clauses joined by and. These clauses are coordinate because they are of the same order or rank in the sentence, each being (if taken singly) an adjective modifier of the noun.

In the second example, the predicate verb reaches is modified by a compound adverbial clause, similarly made up.

A clause is complex when it contains a modifying clause.

1. The polar bear, which lives in the Arctic regions when it is at home, sometimes reaches temperate latitudes.

Here the adjective clause which lives in the Arctic regions when it is at home is complex, for it contains the adverbial clause when it is at home, modifying the verb lives.

Compound Complex Sentences

Two or more independent complex clauses may be joined to make a compound complex sentence.

2. The brown bear, of which there are several varieties, is common in the temperate regions of the Eastern Hemisphere; || and || the polar bear sometimes reaches temperate latitudes when the ice drifts southward.

This is a compound complex sentence, for it consists of two complex clauses joined by the coördinate conjunction and. Each of these two clauses is independent of the other, for each might stand by itself as a complex sentence.

The first complex clause contains an adjective clause, of which there are several varieties, modifying bear; the second contains an adverbial clause, when the ice drifts southward, modifying reaches.

A sentence consisting of two or more independent clauses is also classed as a compound complex sentence if any one of these is complex.

3. The brown bear is common in the temperate regions of the Eastern Hemisphere; || and || the polar bear sometimes reaches temperate latitudes when the ice drifts southward.

4. The brown bear, of which there are several varieties, is common in the temperate regions of the Eastern Hemisphere; || and || the polar bear sometimes reaches temperate latitudes.

Both of these are compound complex sentences. In one, the first clause is simple and the second is complex. In the other, the first clause is complex and the second is simple.

Complex Sentence

The simple sentence may be made complex by means of a subordinate clause used as a modifier.

The polar bear, which lives in the Arctic regions, sometimes reaches temperate latitudes.

In the first example, the simple subject (bear), besides its two adjective modifiers (the and polar), takes a third, the adjective clause which lives in the Arctic regions. The sentence, then, is complex: the main clause is the polar bear sometimes reaches temperate latitudes; the subordinate clause is which lives in the Arctic regions.

The second sentence is also complex. The main clause is the same as in the first (the polar bear sometimes reaches temperate latitudes). The subordinate clause is when the ice drifts southward, an adverbial modifier of the predicate verb reaches.